1/ Some may be wondering: What ever happened to rapid tests? There was a lot of excitement a few months ago and even the FDA seemed to open up.

So where are the tests?

The answer is a constellation of (solvable!) regulatory and market failures detailed in this thread.

The first issue is that hardly any at-home test manufacturers have submitted applications to the FDA.

Why not?

The answer is that most manufactures are choosing to focus on the medical symptomatic market, which is more lucrative and comes with more regulatory certainty.

While the FDA has opened up a bit on asymptomatic testing, it's still far from certain that they will approve a typical asymptomatic test. Manufacturers are worried about rejection, since it is seen as a black eye in the industry, particularly among investors.

FDA approval also takes way too long, often several months!

So when you put it all together, manufacturers don't want to go through a multi-month process that could end up in reputation-damaging rejection, particularly when they could focus on more lucrative alternative projects.

How to solve this? Two things:

1. More government funding for asymptomatic testing could help incentivize applications.

2. The FDA approval process needs to be much faster.

The second issue is that not as many schools and offices are clamoring for these tests as might be expected. Why not?

Again the issue is regulatory uncertainty.

Many schools and business aren't simply unsure whether asymptomatic testing is allowed!

In August, the CMS made a buried announcement that it's OK for places like universities to do point-of-care testing on asymptomatics as long as they followed up any positive results with lab-based confirmatory tests.
https://www.cms.gov/files/document/clia-university-lab-testing.pdf

This is great, but the announcement was buried and ambiguously worded to maybe only be about universities. People aren't really sure whether it applies to their school or business.

The solution here is that the CMS should vocally and clearly extend this guidance to all schools and businesses.

In addition to CMS issues, schools and businesses are dragging their feet because they don't have any guidance about how to use the tests! The WSJ reports that many antigen tests are sitting idle in nursing home because people don't know how to use them. https://www.wsj.com/articles/many-nursing-homes-shun-free-covid-19-testing-equipment-11604769383?mod=hp_lead_pos7

The CDC should provide clear guidelines on how to use these tests for asymptomatic screening.

Instead, the CDC has waffled on the issue, and for some time even discouraged testing on asymptomatics.

The CDC should become a clear proponent with clear guidelines, so that schools and business can do these tests with legal confidence.

In summary. Lots of things are gumming up the works. The solutions are clear:

1. More funding.
2. Faster FDA approval
3. Regulatory clarity from CMS
4. Clear guidance from CDC

Many thanks to @jhuber for explaining this.

cc @ATabarrok @tylercowen @bgurley @nataliexdean @DrLeanaWen @ashishkjha @yayitsrob for a thread detailing the market failures and regulatory failures slowing down rapid tests.

For yet another roadblock slowing down rapid tests, see this thread about the FDA's now-unnecessary requirement for manufacturers to collect data on asymptomatics. https://twitter.com/RapidTests/status/1326600105135382528